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src/config/normalize/lib/wild_wild_path/iterate/recurse.js

@@ -22,7 +22,11 @@ const expandRecursiveToken = function (entry, index) {
   }))
 }
 
-// Handle ** recursion
+// Handle ** recursion.
+// It matches 0, 1 or more levels.
+//  - It can match 0 levels, i.e. the current object
+// It is the same as the union of . * *.* *.*.* and so on.
+// Using both * and ** can express minimum depth, e.g. *.** or *.*.**
 const recurseAnyDeep = function (queryArray, index) {
   const parentQuery = queryArray.slice(0, index)
   const childQuery = queryArray.slice(index)